Final answer:
The mechanical advantage of a pulley system is determined by the number of ropes supporting the load, with each rope adding to the total force applied to the load in a frictionless system.
Step-by-step explanation:
The mechanical advantage (MA) of ropes and pulleys is determined by the number of ropes supporting the load. In a frictionless pulley system, the output force is an integral multiple of the tension in the cable, so the mechanical advantage can be calculated by simply counting the ropes.
For example, if four ropes are attached to the load, the system has a mechanical advantage of approximately four. This means that pulling down with a certain force on one end of the pulley system will apply a multiplied force on the load. It is important to remember that while the force is multiplied, the distance the load is lifted will be less than the length of rope pulled.